Abstract: The Gemini Planet Imager Exoplanet Survey (GPIES) was a direct imaging program aiming to observe 600 young, nearby stars to search for giant planets between 10-100 au. The survey took place between 2014-2019 and resulted in the discovery of a new planet – 51 Eridani b. However, many unconfirmed candidates remain from the survey from the forward-model matched filtering (FMMF) planet detection algorithm. This algorithm allows increased planet detection sensitivity by accounting for distortions in the image when fitting for the planet signal. We have been systematically analyzing all remaining candidates from the FMMF algorithm. Spectra are extracted from each detection and are used to identify the most promising planet candidates. This is achieved by comparing the data with empirical spectra of brown dwarfs and theoretical exoplanet atmosphere models. I will present the latest results from the validation of remaining GPI candidates and, in particular, the detection of HD 143811 AB b, a surprise discovery of a unique system. This new planet is only the second discovered by GPI and is one of only a few directly imaged planets orbiting a tight inner binary. I will share how this system is an excellent laboratory to study planet formation mechanisms through orbital monitoring and the current characterization of both planet and host binary. Lastly, I will discuss how the final vetting process leads to contrast curves for GPIES. Contrast curves, set by detection false positive rate, will demonstrate the impact of GPI on the direct-imaging field and on population statistics of young, Jovian exoplanets.